Antibiotic nodusmicin (U-59,761) is producible in a fermentation under controlled conditions using a biologically pure culture of the microbe Saccharopolyspora hirsuta strain 367, NRRL 12045. This antibiotic is active against various bacteria, including Mycobacterium avium, S. lutea, K. pneumoniae, B. fragilis, and C. perfringens. The structural formula for nodusmicin is shown in Chart I as compound (1).
Antibiotic nargenicin A.sup.1 is disclosed in U.S. Pat. No. 4,148,883, and also described by W. D. Celmer et al., J. Am. Chem. Soc., 1980, 102, 4203-4209. The structural formula for nargenicin A.sup.1 is shown in Chart VI as compound (14).